Fuel injection device for internal combustion engines



H. DINNER March 22, 1932.

FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Feb, 21, 1930 -Whn nlflfl Patented' Mar. 22, 1932 UNITED STATI-:s

PATENT OFFICE HEINRICH DINNER, OF ENNENDA, SWITZERLAND, ASSIGNOR T THE FIRM OF SULZER FRERES SOCIT ANONYME, OF WINTERTHUR, SWITZERLAND FUEL INJECTION DEVICE FOB INTERNAL COMBUSTION ENGINES Application led February 21, 1.930, Serial No.

. 1 zle of the injectipn valve, and is thence discharged through a similar conduit. Except in those cases in which the cooling medium employed is a distillate of a high degree of purity, such for example as distilled water,

arrangements of this known type have the disadvantage that the conduits byreason of their small internal diameter are liable to become" furred or obstructedsso that free circulation of the medium is impeded. Further, the chamber around the nozzle necessarily retards the flow and hampers circulation of the medium at this point in the cooling system, thus reducing the cooling eifect of the medium on the nozzle and in some cases causing the medium surrounding the nozzle to boil and deposit vsuspended impurities, such for example as boiler scale.

' The object of the present invention is to provide an improved construction of cooled fuel injection device in which the above disadvantages wil'! be overcome.

According to the present invention the cooling medium is ctiveyed to and from the injection device which rests on a seat itted in the casing and together with the casing form a tubular cooling chamber through annular chambers arranged one within the other and surrounding the fuel delivery pipe of the nozzle by means of a tubular member subdividing the cooling chamber into two, these annular chambers being in communication with each other at or near the nozzle of the injection valve and one leading cooling medium to, and the other from, the nozzle. The cooling medium during itspassage from one chamber to another is sharply deflected over the nozzle and passes over the outer surface of the nozzle at an increased speed so that the transmission of heat from 430,288, and in Switzerland March 18, 1929.

' the injection valve to the medium surrounding the nozzle is accelerated. One construction of liquid-cooled fuel injection device according to this invention is illustrated by wayof example in the accompanying drawings, in which Figure 1 is a section on the line l-l of Figure 3, showing a portion of the engine cylinder cover. y

Figure 2 is a section on the line 2-2 of Figure 3, and

Figure 3 is a plan.

In the construction illustrated the cylinder head 1 of the engine carries a casing 2 having at its lower end a cap 3 provided with a conical aperture to receive a fuel inection nozzle 4. The nozzle 4 has a central ore 5 communicating with inclined discharge passages 6 and 7 through which fuel is injected in fine jets 8, 9 into the combustion chamber (indicated at 10).

A fuel delivery pipe 11 having relatively thick walls is in screw-threaded engagement with the inner end of the nozzle 4 and presses the latter on its conical seat in the cap 3,

the delivery pipe 11 being in turn held in place by a cover 12 secured to the Casin y studs 13 and 14. The fuel delivery pipe 11 has a central bore 15 which communicates with the bore 16 of a fuel supply pipe 17 which passes through a stung box 18, 19 1n the cover 12.

Screwed into the cover 12 is a tube 25 so dimensioned and arranged coaxial with the fuel delivery pipe 11 that when the injection valve'is in position in the casing 2, two annular concentric chambers 20, 21 are provided which communicate with each other at their lower ends. The upper end of the chamber 2O is sealed by means of a packing 22 and the cover 12 encloses the upper end of the chamber 21.

The cooling medium is admitted through a supply pipe 23 in the direction of the arrow 26 and, iowing down the chamber 20, is sharply deiected at the bottom over the nozv zle 4, as shown by the arrowsi 27 and 28. The medium then passes up thechamber 21 by the arrow 31.

l, cross-sectional area available for the flow of fuel isconsiderably greater than if the'cooling medium were conducted through pipes or v passages of relatively small internal diameter. The chambers and 21 are preferably circular in cross section but if desired these may be of elliptical or other cross-section as desired in accordance with any special conditions.

A fuel injection device according to the present invention can be effectively cooled with a medium, such for example as water, which has not been purified or distilled wlthout risk of the passages for the medium becoming suiciently obstructed to impair free circulation. The fuel injection device described and illustrated has. a further advan-V tage that by removing the studs 13, 14, the cover 12 together with the tube 25, the fuel delivery pipe 11 and nozzle 4 can be withdrawn as a unit after which the removal of deposited impurities both inside the casing 2 andon the tube land pipe 11 is a simple matter.

The sharp'defle'ction of the medium over,

f the nozzle 4 as indicated by the arrows 27 and 28 assiststhe transmission of heat from the nozzle 4 to the cooling medium which surrounds it. `The cooling medium in passing up the chamber 21 imparts to the fuel contained in the fuel delivery pipe 11 some of the heat which the medium has taken from the nozzle 4 so thaty the viscosity of the fuel in the pipe 11 is reduced and the load on the fuel pump reduced accordingly. B v reason of the "rapid transmission of'heat from the nozzle to the medium, evaporation and coking of the fuel in the nozzle is prevented and part of the heat thus imparted to the medium is employed to reduce theviscosity of the fuel before this reaches the nozzle, so that the fuel is maintained at a temperature which is most suitable both for pumping and injection.

I claim:

1. A cooled fuel-injection device for internal combustion engines, comprising a fuelinjeetorvincluding a nozzle, a casing for the fuel-injector, a seat in the lower end thereof, the injector being mounted in the casing with therlower end thereof resting in said seat and being supported by the casing, said injector being readily removable outwardly from the seat,vthe injector andcasing together defining a chamber for cooling fluid surrounding the nozzle of the injector, inlet and outlet means in said chamber for said iuid, a tubular member between said casing and said injector and surrounding the injector, the chamber for the cooling fluid bcing divided into two smaller annular chambers thereby, one of said annular chambers serving to lead the coolingifiuid to the nozzle and the other serving to lead the cooling fluid away from the nozzle.

2. A cooled fuel-injection device for internal combustion engines as in claim 1, wherein the two annular chambers adapted for conveying the cooling medium-communicate with each other near the nozzle, in such a manner as to accelerate the deiiection of the lcooling medium at right angles, to thereby accelerate heat-transfer from the injector to the cooling medium.

3. A cooled fuel-injection device for internal combustion engines comprising a fuelinjector including a nozzle, a casing for the fuel-injector, a seat in the lower end thereof, the injector being mounted in the casing with the lower end thereof resting in said seat and being supported by the casing, the injector and casin together defining a. chamber for cooling uid surrounding the nozzle of the injector, inlet and outlet means in said chamber for said fluid, a tubular member between said casing and said injector and surrounding the injector and ldividing the chamber for the cooling iiuid into two smaller annular chambers which communicate with each other near the nozzle, one of said annular chambers serving to lead the cooling fluid to the nozzle and the other serving to lead the cooling fluid away from the nozzle,

and a cover member, said injector, nozzle unit and tubular member being carried by said cover member.

. In testimony whereof I have affixed my signature.

HEINRICH DINNER. 

